Battery power source

[Ivor]

Hi,

I'm planning on build a power source to support my summer trip to the French Alps. I'm basing it on a 110AH gel battery to give myself enough for a long winter night or two summer nights, I want to box this all up to minimise the cables and condensation on the cables, has anyone tackled this before? got any advise, lessons learnt? good parts to buy ? Things to avoid?

Current equipment list (have I forgotten anything?) :

12V 110AH gel battery
Appropriate Charger
6 marine cigarette sockets
Fuse box
Red LED strip lights
Future expansion to support powered USB hub
Wheels to pull it along (one locking)

[mickw]

Why a locking wheel ? Do you intend setting up on a slope ?
Why LED striplights ? Unless it's to give you illumination, you'll only need one LED to show the outlets are live.

Mount the cigarette sockets in a box, connect to battery with flex and crocodile clips and cart to site on something like this -
http://www.maplin.co.uk/folding-trolley-97489
Can also be used for other stuff.

Don't bother boxing stuff up.

Something that would be easily examined by HMRC could save you problems

[The Thing]

I'm with Mick, easier to show customs and easier to rewire if needed. Condensation isn't a problem, we all leave our batteries and cables out in DSC fields all night with no problems. Clamping terminal connectors are the beez neez. Marine sockets are a good idea, my 4 port car unit went rusty eventually, but it was only £5.99 to replace...

[Ivor]

The battery will also be used for camping to charge phones, campign lights etc and I wanted to keep it out of way of little fingers.

I wanted to add a few switchable red LED strips to provide a little light for setting up in the dark and to avoid kicking the box in the middle of the night.

In the summer I'm planning to set up here 45.8N 6.695E so there will be a slope also I wanted it to be easy for my wife to move it around when camping and I'm not there.

I travel down by car so normally less issues with HMRC.

[Ian]

I did this for a while, for most of the reasons you mentioned. I decided that it was too much to carry all together (wheels or not, it's got to be lifted into the car) and got a pain should you want to use more than one battery. I've built a distribution box based on banana plugs though, I hate cigarette lighter sockets.

[Rocket Pooch]

Ivor,

I still use a biggy batt in the field (the dsc crew have all gone soft), in winter a chemical hand warmer under the battery keeps it nice and warm and the amp output is great:-)  Don't over cook it though.

Chris

[MarkS]

Don't over cook it though.

Could you provide proper cooking instructions?  Mine always end up a bit chewy - maybe they're not microwaveable?

[Mac]

Could you provide proper cooking instructions?

just search youtube for microwave batteries,

there are loads

Too many to post

Mac.

[Ivor]

OK looking through my battery options and it seems a AGM and GEL aren't too different, what do others use? and does anyone have a recommend a supplier?

[MarkS]

it seems a AGM and GEL aren't too different, what do others use?

What's an AGM and what's a GEL?

[Ian]

mechanical methods of keeping the acid in contact with the metal electrodes. Gel batteries use gel, Absorbed glass mat use mats to hold the acid in place.

Ivor, I've killed several gel batteries, due to not keeping them charged. I think nearly everyone now uses leisure batteries, as they're designed to deep discharge without damage. The trade off is they can't produce the amperage like a car battery can. Not completely relevant to us, unless you plan on starting your car with it as well.

[Ivor]

There appears to be two types of marine leisure batteries AGM and GEL with slightly different properties, I found this definition

http://www.batteryfaq.org/

Flat Plate AGM [Absorbed Glass Mat] (Ca/Ca) VRLA

Sealed Absorbed Glass Mat (Ca/Ca) VRLA flat plate car and deep cycle batteries (also know as "starved electrolyte" or "dry") have a very fine fiber Boron-Silicate glass mat between their flat Lead with Calcium alloy in the positive plates and Lead with Calcium alloy in the negative plates. The AGM battery was invented in 1980 and first used in military aircraft in 1985. They have all of the advantages of the "Maintenance Free" (Ca/Ca) batteries plus:

•Much safer then wet batteries (due the hydrogen gas recombination during charging)
•Do not require water
•Lower self-discharge rate (typically 1%-2% per month)
•Longer service life (typically up to twice as long)
•Higher resistance to vibration
•Lower deep discharge failure
•Less forgiving when accidentally overcharged
•Higher bulk charge acceptance rate (which means up to a 15% shorter recharge time and reduced cost)
•Lower tolerance for heat
•Do not require special hazardous shipping
•Can be used in saltwater applications
•Spill proof and can be mounted in virtually any position (because they are sealed)
•Can be used inside a semi-enclosed area, like the passenger compartment or trunk
•Greater terminal corrosion resistance
•Less charging voltage tolerance
•Not subject to sulfation from electrolyte stratification or water loss
•Charging losses of 4% and maximum continuous discharge rate 33% of their capacity
Gel Cell (Ca/Ca) VRLA
Sealed Gel Cell (Ca/Ca) VRLA (Valve Regulated Lead-Acid) deep cycle batteries also use GRT (Gas Recombinant Technology) and were invented in 1934 by Otto Jache and commercially introduced by Sonnenschein in 1957. They use a thickening agent like fumed silica gel to immobilize the electrolyte instead of a liquid electrolyte like wet batteries. Gel Cell batteries have a lot of the same advantages and disadvantages of AGM (Ca/Ca) VRLA batteries and use Lead with Calcium (Ca) alloy positive and Lead with Calcium (Ca) alloy negative plate formulations. When comparing Gel Cell (Ca/Ca) to AGM (Ca/Ca) and Spiral Wound AGM batteries, Gel Cells will typically:
•Have greater ability to withstand a deep discharge, but not temperatures over 100°F (37.8° C) because of the possibility of "thermal runaway"
•Need a 10 to 15 cycle preconditioning or "break-in" period
•Supply less Cold Cranking Amps
•Have 80% of the capacity of a similar sized AGM (Ca/Ca) battery and physically larger
•Require longer recharging times and lower currents
•More forgiving when accidentally overcharged
•Are intolerant of incorrect charging voltages which require special gel cell chargers or gel cell settings
•Produce lower capacity in cold temperatures
•Provide up to 20% more life cycles than AGM VRLA batteries
•Costs more because more expensive to manufacture
•Can loose capacity due to voids between the plates when overcharged
•Sustain charging losses of 4% and maximum continuous discharge rate 25% of their capacity


The key difference being Gel will let you discharge lower with no negative impact but requires longer to charge but are larger.

[Ian] I thought the definition of a Leisure battery was one which has to have a low Crank value(CCD starting to get the lingo) for general power consumption and Gel and AGM form part of that group.  What model battery do you have?

Keeping the battery going seems to be down to have a quality charger, e.g. CTEX MXS 7.0 not cheap mind.

[MarkS]

I use a bog standard wet leisure battery now (not a marine version).  I used to use a standard wet car battery but I killed it pretty quickly because of frequent deep discharging and an el cheapo charger which cooked it.  I now have a quality charger.

Mark

[JohnP]

Gel batteries are EXPENSIVE...!!!!!

[The Thing]

I use a bog standard wet leisure battery now (not a marine version).  I used to use a standard wet car battery but I killed it pretty quickly because of frequent deep discharging and an el cheapo charger which cooked it.  I now have a quality charger.

Mark

Ditto. I've taken my 110Ah battery to France many times just in the boot of the car (well wedged in) with no problems. The battery was around £55, the smart  charger £45. I've had it a few years now. I often use a 5m long cable (80 strand speaker cable) so I don't have to take the battery out of the car.